This invention relates to captive screws of the type generally used to attach a first panel to a second panel, frame or other surface wherein it is desired to keep the fastener in position on the first panel without loose items of hardware. The captive screw is mounted to the upper panel such that the screw stays attached to the panel even when the threads of the screw are fully disengaged from a threaded hole in the second panel to which the first panel is attached.
The present invention is directed toward a new and improved captive screw of a type which has a knob, a screw, and a ferrule. The captive screw is captivated on a panel by the ferrule and as the screw is screwed into a second panel the knob telescopically retracts over the ferrule. A spring may be used which urges the knob and integral screw to its fully retracted position when the captive screw is not attached to the second panel, thereby withdrawing the threads of the screw from the area of the lower panel.
Captive screws of the foregoing type in general are disclosed in, for example, Frattarola, U.S. Pat. No. 5,382,124 and French Patent 1,339,942. These patents depict captive screws of the general type herein but contain different configurations where the screw head mates integrally with the knob of the captive screw.